Impact of CdTe BSF layer on enhancing the efficiency of MoSe₂ solar cell

Molybdenum Diselenide (MoSe₂)-based solar cells have gained significant interest among researchers due to their exceptional semiconducting properties. However, the performance is bottle-necked by band structure mismatches in the back surface field (BSF)/MoSe₂ and MoSe₂/buffer interfaces. This study aims to enhance the performance of a novel Cu/FTO/CdS/MoSe₂/CdTe/Au solar cell and explore the effects of the Cadmium Telluride (CdTe) BSF and CdS buffer layer on key performance parameters such as open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), and power conversion efficiency (PCE). Utilizing SCAPS simulation software, we conducted a comprehensive analysis considering variations in layer thickness, carrier concentration, bulk defect concentration, interface defects, operating temperature, and electrode configuration. Our findings reveal that the device shows good performance at lower carrier concentrations (1 × 10¹⁶ cm⁻³) with a thin (2 μm) MoSe₂ absorber layer. For the Cu/FTO/CdS/MoSe₂/Au reference cell, we estimated a PCE of 21.19%, Voc of 0.605 V, Jsc of 42.82 mA/cm², and FF of 81.67%. In contrast, by introducing CdTe between the MoSe₂ absorber and the rear Au electrode in the Cu/FTO/CdS/MoSe₂/CdTe/Au configuration, we achieved significantly improved performance, with a PCE of 27.05%, Voc of 0.747 V, Jsc of 43.57 mA/cm², and FF of 83.09%. This research offers valuable insights and presents a viable pathway towards realizing cost-effective MoSe₂-based thin-film solar cells with enhanced performance characteristics.